Shit, I'm noticing this myself but thought it was just me. I have a work iPhone 4S on AT&T and a personal iPhone 5 on Sprint. The AT&T lasts 3 days, the Sprint lasts slightly more than 1. But I get significantly more signal with AT&T where I work due to a tower directly on base.--less talk, more music

My iP4 on T-Mobile also chews battery more than it ever did on AT&T. AT&T has great coverage here, albeit 5X5 but overpriced service. Of course then again, Sprint in SoCal is pretty much 0X0...evidently they think deploying LTE to populated areas aside from SFO is repulsive.